Threading-die.



No. 830,736. PATENTED SEPT. 11, 1906. W. B. PEARSON.

THREADING DIE.

APPLIGATION- FILED SEPT. 12, 1902. BBNBWED JUNE 1a, 190e.

WALTER. B. PEAEsoN, or cHIoAeo, ILLINOIS, AssIGNoR To STANDARD SCREW COMPANY, OF DETROIT, MICHIGAN, A CORPORATION OE NEW JERSEY.

THREADiNe-DIE.

Specification of Letters Patent.

Patented Sept. 11, 1906.

Applsation filed September l2. 1902-. Renewed June 13,| 1906 Serial No. 321,503.

To all whom it nfl/Ly concern:

Be it known that I, WALTER B. PEARsoN, a citizen of the United States, and a resident of Chicago, in the county of Cook and State of Illinois, have invented a Threading-Die, of which the following is a specification.

This invention relates to threading-dies,

, and particularly to what are known as openingfdies.

Among the objects of the invention are to provide an opening-die which will be strong, simple, and practical; to provide means to lock the chasers rigidly in operative position so that said die will be uniform and certain in its operation, and to provide means whereby the threading-chaserswill be positively retracted when it is desired to open said'die.

Ar threading-die of my'invention consists of the various features, combinations of features, and details of construction hereinafter described and claimed.

In the accompanying drawings a threadingdie of my invention is fully illustrated.

y heads of which project over and engage suit Figure 1 is a front view of a threading-die of my invention. Fig. 2 is a sectional view thereof on the line 2 2 of Fig. 1, and Eig. 3 is a partial sectional view on the line 3 3 of Fig. 1.

Referring now to the drawings, 1 designates the body of the die. Fitted to suitable guides formed in the body of the die, s o as to be movable toward and from the axis thereof, are a plurality of chasers 2. In the preferable construction shown said chasers 2 are tted to suitable slots 3, formed in the diebody, and are provided with grooves 4, with which engage tongues 5 on said die-body. For convenience of construction the tongues 5 are preferably formed on blocks 6, removably secured in suitable holes or openings in said dieebody. As shown, said blocks 6 are secured in said openings by means of clampingscrews 7, threaded into the die-body 1, the

able shoulders on said blocks 6 and which also are preferably fitted to counterbores formed partly in said blocks and partly in said die-l body.

Suitable stops limit the inward movement of the chasers 2. As shown, said stops consist of overlapping shoulders 8 and 9 on the die-body and on said chasers, respectively. As shown, also, the shoulders 8 are formed by aring 10, fitted to an axial bore in the rear side of thedie-body 1.

Supported so as to be movable toward and from the die-body 1 is a head 111, rigid portions of which engagethe die-chasers 2 to lock them in operative position when said head is at Vone limit of its movement and which are withdrawn from engagement with said die-chasers to permit their retraction to open said die when-said head is at the opposite limit of its movement. In the preferable construction shown the rigid portions of said head 11 for locking the die-chasers 2 in `operative position consist of arms 12 on said head against which the outer ends of said diechasers bear when said arms are in locking position and which in turn bear outwardly against a rigid forward extension or eXtensions of said head 11. In the preferable construction shown, also, the arms 12 are pivoted to the head 11, and the rigid forward eX- tension of said head, against which said arms bear, consists of a casing 13, which incloses the sides of the die-body and prevents access of all chips, grit, and dirt .to the bearing-surfaces thereof, which would tend to interfere with or prevent the designed operation of the varioris operative parts of the die. Primarily to provide for adjusting the positions of the arms 12, and thus the operative positions of vthe die-chasers 2, and incidentally for convenience of-construction, the casing 13 is threaded to the head 11 and the engaging surfaces of said arms and head are inclined or beveled, as clearly shown at 14. The casing 13 may be secured in any desired adjustment by a set-screw 15, threaded through said casing and designed to bear upon a cylindrical portion4 of the head 1l.

At its extreme forward end the bearingsurface 14 on the casing 13 is made to t the die-body as close as is consistent with requisite freedom of movement, thus preventing access of chips, grit, or other dirt between said die-body and casing, particularly to the bearing-surfaces 14 and generally to the interior of the die. As a further safeguard to prevent access of chips and the like to the bearing-surfaces 14 on the arms 12 and casing 13 springs are applied to said arms l2, which operate to maintain said bearing-surfaces in contact under all conditions ofuse. As shown, the ends of said arms 12 are forced outwardly into contact with the bearing-sur- IOO IOS

faces 14 on the casing 13 by spring-rods 16,

secured in the head 11, which project for ward through suitable holes or openings in the die-body and bear against the inner sides of said arms at a distance in front of their pivots. The casing 13 is secured concentric with the die-body 1 by means of a iiange 17 on said die-body, which is slidably fitted to an interior cylindrical bearing-surface 18 on said casing. r- In the preferable construction shown the arms 12 en age the die-chasers 2 directly in line with t e cutting-teeth thereof-in the present case with the front edges thereof.

The die-chasers 2 are advanced into operative position and retracted to open the die when movement is imparted to the head 11 toward and away from the die-body 1 by engaging parts on said die-chasers and on the arms 12, comprising suitable cam-surfaces on one or both thereof. As shown, cam-surfaces 19 and 20 are formed on the die-chasers. The cam-surfaces 19 are disposed in the path of travel of the lower edges of the forward ends of the arms 12 when the die-chasers are retracted and are engaged thereby as the head 11 moves toward the die-body 1, which will operate to advance said die-chasers into operative position in an obvious manner. When saiddie-chasers have been advanced into operative position, the arms 12 pass over the outer ends of the die-chasers, thus positively locking said die-chasers in operative position. The opposed stop-shoulders 8 and 9 likewise o erate to limit the inward movement of sai die-chasers to positions in which the blank will enga e `the die-chasers in a manner to insure t e designed operation thereof. When movement is imparted to the lhead 11 away from the die-body 1 to withdraw the arms 12 from engagement with the die-chasers 2, cam-surfaces 21 on the arms 12 engage the cam-surfaces 20 on the die-chasers just after said die-chasers have been released and will o erate to retract the die-chasers to open the ie. Suitable recesses are provided in both the die-chasers 2 and arms 12 to receive projecting portions of the other.

r1`he arms 12 are secured against inward pivotal movement by suitable stopsas shown, by shoulders 22 on the die-body., formed by making the sections of the slots 3, to which the arms 12 are fitted, wider than the sections thereof to which the die-chasers 21 are fitted. As movement is imparted to thel head 11 away from the die-body 1 the engaging cam-surfaces 20 and 21 will thus operate to positively retract the die-chasers.

Withfthe described construction it is obvious that the arms 12 and casing 13 will always be advanced or retracted together by movement of the head 11 and that in any particular adjustment they will always be in the same positions relatively to each other. It is also obvious that by loosening the `setscrew 15 and screwing the casing farther onto or partially unscrewing it from the head 11 the inclined or beveled surface 14 ofthe case ing 13 will engage the corresponding surfaces on the arms 12 nearer to or farther from the outer ends thereof, thus providing for ad justing the operative positions of the chasers.

2 by forcing said arms nearer together or altion to the arbor 23, as shown, by pins 25, se-

cured in the die-body and fitted to and longitudinally movable in suitable holes formed in the fiange or collar 24, the rear ends thereof being connected to the head 11. As shown, the pins 25 are secured in the die-body merely by a driving fit. Preferably, also, springs are applied to the head 11 adapted to maintain said head normally at the limit of its movement toward the die-body 1, and thus to maintain the die-chasers normally locked in operative position. As shown, this is effected by means of coiled springs 26, in serted between the inner ends of recesses 27 in the head 11, and heads 28 on rods 29, which extend lthrough holes in said head and are threaded into or otherwise rigidly secured to the pins 25 in the die-body 1. The rods 29 connect the head 11 with the diebody, while at the same time the springs 26 provide for movement of said head relatively to said die-body to release the diechasers and to open the die. construction it is obvious that said die will be free to float on the arbor 23 to allow it to accommodate itself to differences between the feed and the pitch of the die. Thus if there is a slight difference between the feed of the die and the pitch of the screw being cut the threading action of the chasers will merely impart bodily movement to the diebody toward or from the blank being threaded, as the feed is less or greater than the pitch of the screw, whereas without provision for such adjustment the threads might be very badly mutilated and the screws rendered worthless commercially or the die broken.

The die is' designed to be operated by means of a lever, (not shown,) a pin on which engages a groove 30, formed in the head 11.

A nut 31, threaded to the arbor 23 in the rear of the head 11, limits the rearward movement of said head on said arbor, thereby insuring that the parts of the die will not be subjected to undue strain, which might break them.

I claim as my invention- 1. In a threading-die, the combination of a With the described` IOO IIO

I 3ro ssojee die-body provided lwith guides or ways, diechasers fitted to and movable along said guides or ways toward and from the axis of the die-body, a head movable toward and from said die-body, arms pivoted on said head which engage said die-chasers to lock them in operative position when said head is moved in one direction and are withdrawn to Ahrelease said die-chasers when said head is moved in the other direction, means to secure said locking-arms against pivotal movement and means for advancing and retracting-said die-chasers comprising engaging parts on said die-chasers and'on said locking-arms comprising suitable cam-surfaces on one thereof.

die-body provided'with guides or ways, diechasers fitted to and movable along said vguides or ways toward and from the axis of the die-body, a head movable toward and from said. die-body, arms pivoted on said head which engage said die-chasers to lock them in operative position when said head is moved in one direction and are withdrawn to release said die-chaserswhen said head is moved in the other direction, means for adjustably limiting the outward movement of said arms and supporting said arms against inward pivotal movement.

3. In a threading-die, the combination of a die-body provided with guides or ways, diechasers fitted to and movable along said guides or ways toward and from the axis of the die-body, a head movable toward and from said die-body, arms on said head which lengage said die-chasers to lock them in operative position when said head is moved in one direction and are withdrawn to release said die-chasers when said head is moved in the other direction, and a casing supported concentric with said die-body which extends over said locking-arms, .said locking-arms and casing being provided with engaging surfaces to provide a rigid? support or backing for said arms.

4. In a threading-die, the combination of a die-body provided with guidesor ways, diechasersfitted to4 and movable along said guides or ways toward and from the axis of the die-body, a head movable toward and yfrom said die-body, arms on said head which engage said die-chasers to lock them in operative position when said head is moved in one direction and are withdrawn to release said die-chasers when said head is moved in the other direction, and a casing adjustably secured. concentric with the die-body which extends over said locking-arms, said lockingarms and casing being provided with engaging surfaces comprising inclined or beveled surfaces on said locking-arms.

5. In a threading-die, the combination of a die-body provided with guides or ways, diechasers fitted to and movable along said 2. In a threading-die, the combination of a guides or ways toward and from the axis of the die-body, a head movable toward and from said die-body, arms on said head which engagesaid die-chasers to lock them in operative position when said head is moved in one direction and are withdrawn to release said die-chasers when said head is moved in the other direction, and a casing on said head which extends over said locking-arms, said locking-arms and casing being provided with engagingsurfaces to provide a rigid support or backing for said arms.

6. In a threading-die, the combination of a die-body provided with guides or ways, diechasers fitted to and movable along said guides or ways toward and from the axis of the die-body, a head movable toward and from said die-body, arms pivoted on said head which engage said die-chasers to lock them in operative position when said head is moved in one direction and. are withdrawn to release said die-chasers when said head is moved in the other direction, means to secure said arms against inward pivotal movement and a casing adjustably secured to said head which extends over said locking-arms, said casing and arms being provided with engaging Surfaces comprising inclined 'or beveled surfaces on said locking-arms.

7. In a threading-die, the combination of a i die-body provided with guides or ways, diechasers fitted to and movable along said guides or ways toward and from the axis of the die-body, a head movable toward. and from said die-body, arms pivoted on said headv which engage said die-chasers to lock them in operative position when said head is moved in one direction and are withdrawn to release said die-chasers when said head is moved in the otherl direction, means to secure said arms against inward pivotal movement, a casing adjustably secured to said' head which extends over said locking-arms, said casing and arms being provided with engaging surfaces comprising inclined or beveled surfaces on said locking-arms, and springs applied to `said locking-arms for maintaining the bearing-surfaces thereof in engagement with their cooperating surfaces on said casing.

8. In a threading-die, the combination `of a die-body provided with guides or ways, die chasers fitted to and movable along said guides or ways toward and from the axis of the die-body, a head movable toward and from said die-body, arms on said head which engage said die-chasers to lock them in operative position when said head is moved in one direction and are withdrawn to release said die-chasers when said head is moved in thc other direction, and a casing on said head which extends over said locking-arms, said locking-arms and casing being provided with engaging surfaces to provide a 'rigid support or backing for said arms and said casing be- IIC ing provided also with a bearing slidably fitted to a cylindrical bearing on the die-body.

9. in a threading-die, the combination of a die-body provided with guides or ways, diechasers fitted to and movable along said guides or ways toward and from the axis of the die-body, a head movable toward and from said die-body, arms pivoted on said head which engage said die-chasers to lock them in operative position when said head is moved in one direction and are withdrawn to release said die-chasers when said head is moved in the other direction, means to sewith a bearing slidably fitted to a cylindrical bearing on the die-body.

10. In a threading-die, the combination of a die-body provided with guides or ways, diechasers fitted to and movable along said guides or ways toward and from the axis of the die-body, a head movable toward and from said dienbody, arms on said head which engage said die-chasers to lock them in operative position when said head is moved in one direction and are withdrawn to release said die-chasers when said head is moved in the other direction, a casing supported concentric with said die-body which extends over said locking-arms, said locking-arms and casing being provided with engaging surfaces to provide a rigid support or backing for said arms and means for advancing and retracting said die-chasers consisting of cooperating parts on said die-chasers and on said head.

l1. ln a threading-die, the combination of a die-body provided with guides or ways, diechasers fitted to and movable along vsaid `guides or ways toward and from the axis of the diebody, a head movable toward and 'from said die-body, arms on said head which engage said die-chasers to lock them in operative position when said head is moved in one direction and are withdrawn to release said die-chasers when said head is moved in the other direction, a casing on said head which extends over said locking-arms7 said locking-arms and casing being provided with engaging surfaces to provide a rigid support or backing for said locking-arms and means for advancing and retracting said die-chasers comprising engaging parts on said die-chasers and on said locking-arms comprising suitable cam-surfaces on one thereof.

12. In a threading-die, the combination of a die-body provided with guides or ways, diechasers fitted to and movable along said guides or ways toward and from the axis of sejrse the diebody, a head movable toward and from said die-body, arms pivoted on said head which engage said die-chasers to lock them in operative position when said head is moved in one direction and are Withdrawn to release said die-chasers when said head is moved in the other direction, stops which limit the inward pivotal movement of said arms, a casing adjustably secured to said head which extends over said locking-arms, said locking-arms and casing being provided with engaging surfaces comprising inclined or beveled surfaces on said arms for adjustably limiting the outward pivotal movement of said locking-arms and means for advancing and retracting said die-chasers comprising engaging parts on said die-chasers and on said locking-arms comprising suitable camsurfaces on one thereof.

13. In a threadingedie, the combination of a die-body7 provided with guides or ways, diechasers fitted to and movable along said guides or ways toward and from the axis of the die-body7 a head movable toward and from said die-body, arms pivoted on said head which engage said die-chasers to lock them in operative position when said head is moved in one direction and are withdrawn to release said di e-chasers when said head is moved in the other direction, stops which limit the in- Ward pivotal movement of said arms, a casing threaded to said head which extends over said locking-arms, said locking-arms and casing being provided with engaging surfaces comprising inclined or beveled surfaces on said arms for adjustably limiting the out- Ward pivotal movement of said locking-arms and means for advancing and retracting said die-chasers comprising engaging parts on said die-chasers and on said locking-arms comprising suitable cam surfaces on one thereof.

14. In a threading-die7 the combination of a die-body provided-with holes or openings, a blocl of less thickness than the width of said holes or openings removably secured to a side of each of said openings, die-chasers slidably fitted to the spaces between said blocks and the opposite sides of said holes or openings and movable therein toward and from the axis of the die-body, engaging tongues andfgrooves on said die-chasers and removable blocks, means for advancing and retracting said die-chasers and means for securing said die-chasers in operative position.

15. In a threading-die7 the combination of a die-body provided with holes or openings7 a block of less thickness than the width of said holes or openings inserted against a side of each of said holes or openings7 clampingscrews threaded into said die-body, the heads of which are fitted to counterbores formed partly in said blocks-and partly in the die-body shoulders on which engage corresponding shoulders on said blocksI die- IOO IIO

chasers slidably ltted to the spaces between said blocks and the opposite sides of said holes or openings and movable therein toward and from the axis of the die-body, engaging tongues and grooves on said diechasers and removable blocks, means for advancing and retracting said die-chasers and means -for securing said die-chasers in operative position.

16. In a threading-die, the combination of a die-body provided with guides or ways, and a rearward axial bore, die-chasers tted to and movable along said guides or ways toward and from the axis of said die-body, a ring iitted to the axial bore in said die-body which projects into the path of travel of rigid portions of said die-chasers, means to advance and retract said die-chasers and means to secure said chasers in operative position. p

17. In a threading-die, the combination of an arbor, a die-body and a head fitted to and longitudinally movable on said arbor, means to secure said die-body against rotation on said arbor, a stop which limits the movement of said die-body and head lengthwise of said arbor, yielding connection between said diebody and head whereby said head is maintained normally at one-limit of its movement relatively to said die-body, guides or ways on said die-body, die-chasers fitted to and movable along said guides or ways toward and `from the axis of said die-body, rigidly-supported arms on said head which engage said die-chasers to loclr them in operative position when said head is moved in one direction and are withdrawn to release said die-chasers when said head is moved in the other direction, and means for advancing and retracting saidv die-chasers comprising engaging parts on said die-chasers and on said locking-arms comprising suitable cam e surfaces on one thereof.

18. In a threading-die, the combination of an arbor, a die-body, a head fitted to and longitudinally movable on said arbor, a collar on said arbor between said die-body and sleeve, pins secured in said die-body which are `fitted to and longitudinally movable in holes or openings in said collar, rods secured to said pins, springs inserted between shoulders on said rods and the bottoms of recesses formed in said head whereby said springs will maintain said head normally at one limit of its movementrelatively to said diebody, guides or ways on said die-body, diechasers iitted to and movable along said guides or ways toward and from the axis of said die-body, rigidly-supported arms on said head which engage said die-chasers to lock them in operative position when said head is moved in one 'direction and are withdrawn to 4 my invention I affix my signature, in presence of two subscribing witnesses, this 19th day of August, A. D. 1902.-

WAIJTER B. PIGARSON. Witnesses:

M. S. SOMERVILLE, ARTHUR W. ANDREWS, Jr. 

